Governor for fluid motors



Feb. 28, 1933. J. E. ERICKSON GOVERNOR FOR FLUID MOTORS Filed Jan; 16,19:52 2 Sheets-Sheet 1 (ttomeglI J'Ill"` Feb. 28, 1933. J. E. ERICKSONGOVERNORAFOR FLUID MOTORS 2 Sheefs-Sheet 2 Filed Jan. 16, 1932/ff/PaieL/ted Feb. 2s, 1933 UNITED STATES PATENT OFFICE JOHN E.ERICKSON, 0F MADISON, WISCONSIN, ASSIGNOR T0 MADISON-KIP? CORPORA- TION,OF MADISON, WISCONSIN, A CORPORATION OF WISCONSIN f GOVERNOR ron FLUIDmorons Application led January 16, 1932. Serial No. 587,111.

This invention relates to centrifugal throttling overnors particularlyintended for use witg rotary air driven-grinders, but susceptible of amuch wider application.

As illustrated, the governor is arranged to throttle the exhaust flowfrom an air turbine, but so far as the governor is concerned the inletflow might be regulated. `The governor may be used also with aconsiderable range of pressure fluids.

A feature of particular importance is the fact that the governor isformed exclusively of metal. l

Other features to which importance is attached reside in the form andarrangement of the parts to simplify manufacture and maintenance andensure uniform governing characteristics in devices manufactured on amass production basis. Experience Y shows that the governor willregulate a motor running at 28000 R. P. M. t0 within 1000 R. P. M. (01'about 3.6%).

The preferred embodiment of the invention as applied to an air drivengrinder of known type is illustrated in the accompanying drawings, inwhich:-

Fig. 1 is a longitudinal section through the grinder (assumed to be atrest) Fig. 2 is an enlarged fragmentary view of the governor as itappears in Fig. 1;

Fig. 3 is a view similar to Fig. 2, but illus- 5 trating the positionassumed by the governor iin ers when the grinder overspeeds; F ig. 4 isa section on the line 4-4 of Figj is. a perspective view of the flexiblefinger unit; p

Fi 6 is a view similar to Fig. 2, showing a m ification;l

Figs. 7 and 8 are views similar to Figs. 2 and 3 showing anothermodification;

Fig. 9 is a section on the line 9-9 of Fig. 8, the normal position ofthe governor fingers being indicated in dotted lines.

Referring first to Fig. 1, the casing of the inder includes an enlargedbody 11 in which the turbine wheel is enclosed and a concentric slenderextension 12, th-rough The shaft 13 turns in ball bearings 14 and 15 ofthe annular type and is supported by a conical thrust bearing 16 mountedon the removable head 17. The thrust bearing is adjustable.

The air supply connection is shown at 18 and flow is controlled by aswiveled valve or cock 19 actuated by finger piece 21. yAfter passingvalve 19, -the air passes through passages 22 to nozzles 23, throughwhich it is discharged against buckets 24 formed in the fiat face of therunner 25 of the turbine. The runner 25 is fixed on shaft 13.

The air discharges around the periphery of runner 25,` flows through theannular space between the shaft 13 and tubular extension 12 and passesto atmosphere through ports 26.

The shaft 13 carries a chuck 27 which receives stems 28 on which.grinding Ywheels such as 29 are mounted. l

The grinder above described is 1 now in commercial use and well known.

To govern the rotary speed of such grinders, it has heretofore beenproposed to throttle variably the fluid (exhaust air) flowing throughthe extension 12. The present invention operates on that generalprinciple.

Within `the extension 12 an annular rib 31 is formed. This is circularon its inner margin and embraces closely, but. without actual contact, acylindrical skirt 32 projecting from a hub 33 tightly fixed on shaft 13.There is an annular series of ports 34, four being shown, which extendthrough the skirt 32 and form the sole path for fluid flow, except forsuch leakage as occurs between skirt 32 and rib 31.

Also fixed on shaft13 is a second hub 35 from which extend slenderflexible fingers 36 whose free ends'project within the skirt 32. Thereis one finger 36 for each port 34, and, when the fingers 36 are flexedoutwardly, they throttle or close corresponding port 34 which theyoverlie.

- The hub 35 and fingers 36 are integral and a convenient way to formthis part is to machine the hub with a slender tubular extension orsleeve, and then slot this sleeve. .The shaft 13 is reduced beneath thefingers as indicated at 37 (see Fig. 3) to afford clearance for any oilor solid particles which might aocumulate and tend to limit the inwardmo' tion of the fingers.

Figs. 3 and Lshow the fingers 36 in their outermost position, and Fig. 4indicates that they do not conform strictly to the internal curvature ofshirt 321.

.If such conformity is found important in a particular case, the fingersare locked in an expanded condition and then machined to the internalcurvature of skirt 32. This produces the modified structure of Figs. 7to 9 in which the taper at 38 shows the effect of the final machiningstep. Fig. 9 illustrates the complete contact thus secured between thefingers and skirt.

The modification in Fig. 6 involves merely the reversal of the skirt andfingers relatively to the direction of dow. Such an arrangement isentirely operative, but it is considered better to oppose inward flow ofthe pressure fluid to the outward centrifugal tendency of the fingers.

Various modifications are possible without departure from the invention.

l/Vhat is claimed is l. In a governor for pressure @Huid actuatedmotors, the combination of a tubular casing through whichactuating'pressure vfluid flows; a .haft arranged to be driven by agoverned motor and extending coaxlally through said tubular casing; amember fixed on said shaft to rotate therewith and substani tiallyfilling the annular interval between4 the shaft and easing, said memberbeingv ported to permit passage of the major portion of said fluidtherethrough; and a resilient metal means also mounted on said shaft toturn therewith and adapted to be flexed by centrifugal force to obstructpassage of fluid through said ported member.

2. In a governor for pressure lluid actuated motors, the combination ofa tubular casing through which actuating pressure fluid flows; a shaftarranged to be driven bythe governed motor and extending coaxiallythrough said tubular easing; a member fixed on said shaft to rotatetherewith and substantially filling the annular interval between theshaft and casing, said member having ports through which the majorportion of said fluid flows; and a plurality of flexible metallicfingers also mounted on said shaft to turn therewith and adapted to beflex-ed by centrifugal force into obstructing relationto said ports.

3. The combination of claim 2 further characterized in that there is aflexible nger corresponding to each of said ports.

4. In a governor for pressure fluid actuated motors, the combination ofa tubular cas# ing through, which actuating pressure fluid flows; nashaft arranged to be driven by the governed motor, and extendingcoaxially through said tubular casing; a member fixed vincanta on saidshaft to rotate therewith, said member having a hollow skirt interposedbetween the casing and the shaft which at its margin is juxtaposed tosaid casing, said skirt having ports through which the major portion ofsaid pressure fluid flows; and a plurality of flexible metallic lingerseach fixed at one end to said shaft and projecting at its free end intosaid skirt, said lingers when flexed by centrifugal force serving tothrottle said ports.

5. The combination of cla-im i further characterized in that thepressure fluid in passing through said ports flows toward the axis ofthe shaft.

6. The combination of claim l further charn acterized in that theinterior surface of said 'extension on a hub connected with said shaft.

In testimony whereof I have signed my name to this specification.

Jon-N E. nRroKsoN.

